1 /* $OpenBSD: netcat.c,v 1.157 2016/07/01 00:29:14 bcook Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <netdb.h> 49 #include <poll.h> 50 #include <signal.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <unistd.h> 57 #include <tls.h> 58 #include "atomicio.h" 59 60 #define PORT_MAX 65535 61 #define UNIX_DG_TMP_SOCKET_SIZE 19 62 63 #define POLL_STDIN 0 64 #define POLL_NETOUT 1 65 #define POLL_NETIN 2 66 #define POLL_STDOUT 3 67 #define BUFSIZE 16384 68 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 69 70 #define TLS_LEGACY (1 << 1) 71 #define TLS_NOVERIFY (1 << 2) 72 #define TLS_NONAME (1 << 3) 73 #define TLS_CCERT (1 << 4) 74 75 /* Command Line Options */ 76 int dflag; /* detached, no stdin */ 77 int Fflag; /* fdpass sock to stdout */ 78 unsigned int iflag; /* Interval Flag */ 79 int kflag; /* More than one connect */ 80 int lflag; /* Bind to local port */ 81 int Nflag; /* shutdown() network socket */ 82 int nflag; /* Don't do name look up */ 83 char *Pflag; /* Proxy username */ 84 char *pflag; /* Localport flag */ 85 int rflag; /* Random ports flag */ 86 char *sflag; /* Source Address */ 87 int tflag; /* Telnet Emulation */ 88 int uflag; /* UDP - Default to TCP */ 89 int vflag; /* Verbosity */ 90 int xflag; /* Socks proxy */ 91 int zflag; /* Port Scan Flag */ 92 int Dflag; /* sodebug */ 93 int Iflag; /* TCP receive buffer size */ 94 int Oflag; /* TCP send buffer size */ 95 int Sflag; /* TCP MD5 signature option */ 96 int Tflag = -1; /* IP Type of Service */ 97 int rtableid = -1; 98 99 int usetls; /* use TLS */ 100 char *Cflag; /* Public cert file */ 101 char *Kflag; /* Private key file */ 102 char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 103 int tls_cachanged; /* Using non-default CA file */ 104 int TLSopt; /* TLS options */ 105 char *tls_expectname; /* required name in peer cert */ 106 char *tls_expecthash; /* required hash of peer cert */ 107 uint8_t *cacert; 108 size_t cacertlen; 109 uint8_t *privkey; 110 size_t privkeylen; 111 uint8_t *pubcert; 112 size_t pubcertlen; 113 114 int timeout = -1; 115 int family = AF_UNSPEC; 116 char *portlist[PORT_MAX+1]; 117 char *unix_dg_tmp_socket; 118 int ttl = -1; 119 int minttl = -1; 120 121 void atelnet(int, unsigned char *, unsigned int); 122 void build_ports(char *); 123 void help(void); 124 int local_listen(char *, char *, struct addrinfo); 125 void readwrite(int, struct tls *); 126 void fdpass(int nfd) __attribute__((noreturn)); 127 int remote_connect(const char *, const char *, struct addrinfo); 128 int timeout_connect(int, const struct sockaddr *, socklen_t); 129 int socks_connect(const char *, const char *, struct addrinfo, 130 const char *, const char *, struct addrinfo, int, const char *); 131 int udptest(int); 132 int unix_bind(char *, int); 133 int unix_connect(char *); 134 int unix_listen(char *); 135 void set_common_sockopts(int, int); 136 int map_tos(char *, int *); 137 int map_tls(char *, int *); 138 void report_connect(const struct sockaddr *, socklen_t, char *); 139 void report_tls(struct tls *tls_ctx, char * host, char *tls_expectname); 140 void usage(int); 141 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 142 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 143 void tls_setup_client(struct tls *, int, char *); 144 struct tls *tls_setup_server(struct tls *, int, char *); 145 146 int 147 main(int argc, char *argv[]) 148 { 149 int ch, s = -1, ret, socksv; 150 char *host, *uport; 151 struct addrinfo hints; 152 struct servent *sv; 153 socklen_t len; 154 struct sockaddr_storage cliaddr; 155 char *proxy; 156 const char *errstr, *proxyhost = "", *proxyport = NULL; 157 struct addrinfo proxyhints; 158 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 159 struct tls_config *tls_cfg = NULL; 160 struct tls *tls_ctx = NULL; 161 162 ret = 1; 163 socksv = 5; 164 host = NULL; 165 uport = NULL; 166 sv = NULL; 167 168 signal(SIGPIPE, SIG_IGN); 169 170 while ((ch = getopt(argc, argv, 171 "46C:cDde:FH:hI:i:K:klM:m:NnO:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) { 172 switch (ch) { 173 case '4': 174 family = AF_INET; 175 break; 176 case '6': 177 family = AF_INET6; 178 break; 179 case 'U': 180 family = AF_UNIX; 181 break; 182 case 'X': 183 if (strcasecmp(optarg, "connect") == 0) 184 socksv = -1; /* HTTP proxy CONNECT */ 185 else if (strcmp(optarg, "4") == 0) 186 socksv = 4; /* SOCKS v.4 */ 187 else if (strcmp(optarg, "5") == 0) 188 socksv = 5; /* SOCKS v.5 */ 189 else 190 errx(1, "unsupported proxy protocol"); 191 break; 192 case 'C': 193 Cflag = optarg; 194 break; 195 case 'c': 196 usetls = 1; 197 break; 198 case 'd': 199 dflag = 1; 200 break; 201 case 'e': 202 tls_expectname = optarg; 203 break; 204 case 'F': 205 Fflag = 1; 206 break; 207 case 'H': 208 tls_expecthash = optarg; 209 break; 210 case 'h': 211 help(); 212 break; 213 case 'i': 214 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 215 if (errstr) 216 errx(1, "interval %s: %s", errstr, optarg); 217 break; 218 case 'K': 219 Kflag = optarg; 220 break; 221 case 'k': 222 kflag = 1; 223 break; 224 case 'l': 225 lflag = 1; 226 break; 227 case 'M': 228 ttl = strtonum(optarg, 0, 255, &errstr); 229 if (errstr) 230 errx(1, "ttl is %s", errstr); 231 break; 232 case 'm': 233 minttl = strtonum(optarg, 0, 255, &errstr); 234 if (errstr) 235 errx(1, "minttl is %s", errstr); 236 break; 237 case 'N': 238 Nflag = 1; 239 break; 240 case 'n': 241 nflag = 1; 242 break; 243 case 'P': 244 Pflag = optarg; 245 break; 246 case 'p': 247 pflag = optarg; 248 break; 249 case 'R': 250 tls_cachanged = 1; 251 Rflag = optarg; 252 break; 253 case 'r': 254 rflag = 1; 255 break; 256 case 's': 257 sflag = optarg; 258 break; 259 case 't': 260 tflag = 1; 261 break; 262 case 'u': 263 uflag = 1; 264 break; 265 case 'V': 266 rtableid = (int)strtonum(optarg, 0, 267 RT_TABLEID_MAX, &errstr); 268 if (errstr) 269 errx(1, "rtable %s: %s", errstr, optarg); 270 break; 271 case 'v': 272 vflag = 1; 273 break; 274 case 'w': 275 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 276 if (errstr) 277 errx(1, "timeout %s: %s", errstr, optarg); 278 timeout *= 1000; 279 break; 280 case 'x': 281 xflag = 1; 282 if ((proxy = strdup(optarg)) == NULL) 283 err(1, NULL); 284 break; 285 case 'z': 286 zflag = 1; 287 break; 288 case 'D': 289 Dflag = 1; 290 break; 291 case 'I': 292 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 293 if (errstr != NULL) 294 errx(1, "TCP receive window %s: %s", 295 errstr, optarg); 296 break; 297 case 'O': 298 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 299 if (errstr != NULL) 300 errx(1, "TCP send window %s: %s", 301 errstr, optarg); 302 break; 303 case 'S': 304 Sflag = 1; 305 break; 306 case 'T': 307 errstr = NULL; 308 errno = 0; 309 if (map_tos(optarg, &Tflag)) 310 break; 311 if (map_tls(optarg, &TLSopt)) 312 break; 313 if (strlen(optarg) > 1 && optarg[0] == '0' && 314 optarg[1] == 'x') 315 Tflag = (int)strtol(optarg, NULL, 16); 316 else 317 Tflag = (int)strtonum(optarg, 0, 255, 318 &errstr); 319 if (Tflag < 0 || Tflag > 255 || errstr || errno) 320 errx(1, "illegal tos/tls value %s", optarg); 321 break; 322 default: 323 usage(1); 324 } 325 } 326 argc -= optind; 327 argv += optind; 328 329 if (rtableid >= 0) 330 if (setrtable(rtableid) == -1) 331 err(1, "setrtable"); 332 333 if (family == AF_UNIX) { 334 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 335 err(1, "pledge"); 336 } else if (Fflag) { 337 if (Pflag) { 338 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 339 err(1, "pledge"); 340 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 341 err(1, "pledge"); 342 } else if (Pflag) { 343 if (pledge("stdio inet dns tty", NULL) == -1) 344 err(1, "pledge"); 345 } else if (usetls) { 346 if (pledge("stdio rpath inet dns", NULL) == -1) 347 err(1, "pledge"); 348 } else if (pledge("stdio inet dns", NULL) == -1) 349 err(1, "pledge"); 350 351 /* Cruft to make sure options are clean, and used properly. */ 352 if (argv[0] && !argv[1] && family == AF_UNIX) { 353 host = argv[0]; 354 uport = NULL; 355 } else if (argv[0] && !argv[1]) { 356 if (!lflag) 357 usage(1); 358 uport = argv[0]; 359 host = NULL; 360 } else if (argv[0] && argv[1]) { 361 host = argv[0]; 362 uport = argv[1]; 363 } else 364 usage(1); 365 366 if (lflag && sflag) 367 errx(1, "cannot use -s and -l"); 368 if (lflag && pflag) 369 errx(1, "cannot use -p and -l"); 370 if (lflag && zflag) 371 errx(1, "cannot use -z and -l"); 372 if (!lflag && kflag) 373 errx(1, "must use -l with -k"); 374 if (uflag && usetls) 375 errx(1, "cannot use -c and -u"); 376 if ((family == AF_UNIX) && usetls) 377 errx(1, "cannot use -c and -U"); 378 if ((family == AF_UNIX) && Fflag) 379 errx(1, "cannot use -F and -U"); 380 if (Fflag && usetls) 381 errx(1, "cannot use -c and -F"); 382 if (TLSopt && !usetls) 383 errx(1, "you must specify -c to use TLS options"); 384 if (Cflag && !usetls) 385 errx(1, "you must specify -c to use -C"); 386 if (Kflag && !usetls) 387 errx(1, "you must specify -c to use -K"); 388 if (tls_cachanged && !usetls) 389 errx(1, "you must specify -c to use -R"); 390 if (tls_expecthash && !usetls) 391 errx(1, "you must specify -c to use -H"); 392 if (tls_expectname && !usetls) 393 errx(1, "you must specify -c to use -e"); 394 395 /* Get name of temporary socket for unix datagram client */ 396 if ((family == AF_UNIX) && uflag && !lflag) { 397 if (sflag) { 398 unix_dg_tmp_socket = sflag; 399 } else { 400 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 401 UNIX_DG_TMP_SOCKET_SIZE); 402 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 403 err(1, "mktemp"); 404 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 405 } 406 } 407 408 /* Initialize addrinfo structure. */ 409 if (family != AF_UNIX) { 410 memset(&hints, 0, sizeof(struct addrinfo)); 411 hints.ai_family = family; 412 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 413 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 414 if (nflag) 415 hints.ai_flags |= AI_NUMERICHOST; 416 } 417 418 if (xflag) { 419 if (uflag) 420 errx(1, "no proxy support for UDP mode"); 421 422 if (lflag) 423 errx(1, "no proxy support for listen"); 424 425 if (family == AF_UNIX) 426 errx(1, "no proxy support for unix sockets"); 427 428 /* XXX IPv6 transport to proxy would probably work */ 429 if (family == AF_INET6) 430 errx(1, "no proxy support for IPv6"); 431 432 if (sflag) 433 errx(1, "no proxy support for local source address"); 434 435 proxyhost = strsep(&proxy, ":"); 436 proxyport = proxy; 437 438 memset(&proxyhints, 0, sizeof(struct addrinfo)); 439 proxyhints.ai_family = family; 440 proxyhints.ai_socktype = SOCK_STREAM; 441 proxyhints.ai_protocol = IPPROTO_TCP; 442 if (nflag) 443 proxyhints.ai_flags |= AI_NUMERICHOST; 444 } 445 446 if (usetls) { 447 if (Rflag && (cacert = tls_load_file(Rflag, &cacertlen, NULL)) == NULL) 448 errx(1, "unable to load root CA file %s", Rflag); 449 if (Cflag && (pubcert = tls_load_file(Cflag, &pubcertlen, NULL)) == NULL) 450 errx(1, "unable to load TLS certificate file %s", Cflag); 451 if (Kflag && (privkey = tls_load_file(Kflag, &privkeylen, NULL)) == NULL) 452 errx(1, "unable to load TLS key file %s", Kflag); 453 454 if (Pflag) { 455 if (pledge("stdio inet dns tty", NULL) == -1) 456 err(1, "pledge"); 457 } else if (pledge("stdio inet dns", NULL) == -1) 458 err(1, "pledge"); 459 460 if (tls_init() == -1) 461 errx(1, "unable to initialize TLS"); 462 if ((tls_cfg = tls_config_new()) == NULL) 463 errx(1, "unable to allocate TLS config"); 464 if (Rflag && tls_config_set_ca_mem(tls_cfg, cacert, cacertlen) == -1) 465 errx(1, "unable to set root CA file %s", Rflag); 466 if (Cflag && tls_config_set_cert_mem(tls_cfg, pubcert, pubcertlen) == -1) 467 errx(1, "unable to set TLS certificate file %s", Cflag); 468 if (Kflag && tls_config_set_key_mem(tls_cfg, privkey, privkeylen) == -1) 469 errx(1, "unable to set TLS key file %s", Kflag); 470 if (TLSopt & TLS_LEGACY) { 471 tls_config_set_protocols(tls_cfg, TLS_PROTOCOLS_ALL); 472 tls_config_set_ciphers(tls_cfg, "legacy"); 473 } 474 if (!lflag && (TLSopt & TLS_CCERT)) 475 errx(1, "clientcert is only valid with -l"); 476 if (TLSopt & TLS_NONAME) 477 tls_config_insecure_noverifyname(tls_cfg); 478 if (TLSopt & TLS_NOVERIFY) { 479 if (tls_expecthash != NULL) 480 errx(1, "-H and -T noverify may not be used" 481 "together"); 482 tls_config_insecure_noverifycert(tls_cfg); 483 } 484 } 485 if (lflag) { 486 struct tls *tls_cctx = NULL; 487 int connfd; 488 ret = 0; 489 490 if (family == AF_UNIX) { 491 if (uflag) 492 s = unix_bind(host, 0); 493 else 494 s = unix_listen(host); 495 } 496 497 if (usetls) { 498 tls_config_verify_client_optional(tls_cfg); 499 if ((tls_ctx = tls_server()) == NULL) 500 errx(1, "tls server creation failed"); 501 if (tls_configure(tls_ctx, tls_cfg) == -1) 502 errx(1, "tls configuration failed (%s)", 503 tls_error(tls_ctx)); 504 } 505 /* Allow only one connection at a time, but stay alive. */ 506 for (;;) { 507 if (family != AF_UNIX) 508 s = local_listen(host, uport, hints); 509 if (s < 0) 510 err(1, NULL); 511 /* 512 * For UDP and -k, don't connect the socket, let it 513 * receive datagrams from multiple socket pairs. 514 */ 515 if (uflag && kflag) 516 readwrite(s, NULL); 517 /* 518 * For UDP and not -k, we will use recvfrom() initially 519 * to wait for a caller, then use the regular functions 520 * to talk to the caller. 521 */ 522 else if (uflag && !kflag) { 523 int rv, plen; 524 char buf[16384]; 525 struct sockaddr_storage z; 526 527 len = sizeof(z); 528 plen = 2048; 529 rv = recvfrom(s, buf, plen, MSG_PEEK, 530 (struct sockaddr *)&z, &len); 531 if (rv < 0) 532 err(1, "recvfrom"); 533 534 rv = connect(s, (struct sockaddr *)&z, len); 535 if (rv < 0) 536 err(1, "connect"); 537 538 if (vflag) 539 report_connect((struct sockaddr *)&z, len, NULL); 540 541 readwrite(s, NULL); 542 } else { 543 len = sizeof(cliaddr); 544 connfd = accept4(s, (struct sockaddr *)&cliaddr, 545 &len, SOCK_NONBLOCK); 546 if (connfd == -1) { 547 /* For now, all errnos are fatal */ 548 err(1, "accept"); 549 } 550 if (vflag) 551 report_connect((struct sockaddr *)&cliaddr, len, 552 family == AF_UNIX ? host : NULL); 553 if ((usetls) && 554 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 555 readwrite(connfd, tls_cctx); 556 if (!usetls) 557 readwrite(connfd, NULL); 558 if (tls_cctx) { 559 int i; 560 561 do { 562 i = tls_close(tls_cctx); 563 } while (i == TLS_WANT_POLLIN || 564 i == TLS_WANT_POLLOUT); 565 tls_free(tls_cctx); 566 tls_cctx = NULL; 567 } 568 close(connfd); 569 } 570 if (family != AF_UNIX) 571 close(s); 572 else if (uflag) { 573 if (connect(s, NULL, 0) < 0) 574 err(1, "connect"); 575 } 576 577 if (!kflag) 578 break; 579 } 580 } else if (family == AF_UNIX) { 581 ret = 0; 582 583 if ((s = unix_connect(host)) > 0 && !zflag) { 584 readwrite(s, NULL); 585 close(s); 586 } else 587 ret = 1; 588 589 if (uflag) 590 unlink(unix_dg_tmp_socket); 591 exit(ret); 592 593 } else { 594 int i = 0; 595 596 /* Construct the portlist[] array. */ 597 build_ports(uport); 598 599 /* Cycle through portlist, connecting to each port. */ 600 for (s = -1, i = 0; portlist[i] != NULL; i++) { 601 if (s != -1) 602 close(s); 603 604 if (usetls) { 605 if ((tls_ctx = tls_client()) == NULL) 606 errx(1, "tls client creation failed"); 607 if (tls_configure(tls_ctx, tls_cfg) == -1) 608 errx(1, "tls configuration failed (%s)", 609 tls_error(tls_ctx)); 610 } 611 if (xflag) 612 s = socks_connect(host, portlist[i], hints, 613 proxyhost, proxyport, proxyhints, socksv, 614 Pflag); 615 else 616 s = remote_connect(host, portlist[i], hints); 617 618 if (s == -1) 619 continue; 620 621 ret = 0; 622 if (vflag || zflag) { 623 /* For UDP, make sure we are connected. */ 624 if (uflag) { 625 if (udptest(s) == -1) { 626 ret = 1; 627 continue; 628 } 629 } 630 631 /* Don't look up port if -n. */ 632 if (nflag) 633 sv = NULL; 634 else { 635 sv = getservbyport( 636 ntohs(atoi(portlist[i])), 637 uflag ? "udp" : "tcp"); 638 } 639 640 fprintf(stderr, 641 "Connection to %s %s port [%s/%s] " 642 "succeeded!\n", host, portlist[i], 643 uflag ? "udp" : "tcp", 644 sv ? sv->s_name : "*"); 645 } 646 if (Fflag) 647 fdpass(s); 648 else { 649 if (usetls) 650 tls_setup_client(tls_ctx, s, host); 651 if (!zflag) 652 readwrite(s, tls_ctx); 653 if (tls_ctx) { 654 int j; 655 656 do { 657 j = tls_close(tls_ctx); 658 } while (j == TLS_WANT_POLLIN || 659 j == TLS_WANT_POLLOUT); 660 tls_free(tls_ctx); 661 tls_ctx = NULL; 662 } 663 } 664 } 665 } 666 667 if (s != -1) 668 close(s); 669 670 tls_config_free(tls_cfg); 671 672 exit(ret); 673 } 674 675 /* 676 * unix_bind() 677 * Returns a unix socket bound to the given path 678 */ 679 int 680 unix_bind(char *path, int flags) 681 { 682 struct sockaddr_un s_un; 683 int s, save_errno; 684 685 /* Create unix domain socket. */ 686 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 687 0)) < 0) 688 return (-1); 689 690 memset(&s_un, 0, sizeof(struct sockaddr_un)); 691 s_un.sun_family = AF_UNIX; 692 693 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 694 sizeof(s_un.sun_path)) { 695 close(s); 696 errno = ENAMETOOLONG; 697 return (-1); 698 } 699 700 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 701 save_errno = errno; 702 close(s); 703 errno = save_errno; 704 return (-1); 705 } 706 return (s); 707 } 708 709 void 710 tls_setup_client(struct tls *tls_ctx, int s, char *host) 711 { 712 int i; 713 714 if (tls_connect_socket(tls_ctx, s, 715 tls_expectname ? tls_expectname : host) == -1) { 716 errx(1, "tls connection failed (%s)", 717 tls_error(tls_ctx)); 718 } 719 do { 720 if ((i = tls_handshake(tls_ctx)) == -1) 721 errx(1, "tls handshake failed (%s)", 722 tls_error(tls_ctx)); 723 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 724 if (vflag) 725 report_tls(tls_ctx, host, tls_expectname); 726 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 727 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 728 errx(1, "peer certificate is not %s", tls_expecthash); 729 } 730 731 struct tls * 732 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 733 { 734 struct tls *tls_cctx; 735 736 if (tls_accept_socket(tls_ctx, &tls_cctx, 737 connfd) == -1) { 738 warnx("tls accept failed (%s)", 739 tls_error(tls_ctx)); 740 tls_cctx = NULL; 741 } else { 742 int i; 743 744 do { 745 if ((i = tls_handshake(tls_cctx)) == -1) 746 warnx("tls handshake failed (%s)", 747 tls_error(tls_cctx)); 748 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 749 } 750 if (tls_cctx) { 751 int gotcert = tls_peer_cert_provided(tls_cctx); 752 753 if (vflag && gotcert) 754 report_tls(tls_cctx, host, tls_expectname); 755 if ((TLSopt & TLS_CCERT) && !gotcert) 756 warnx("No client certificate provided"); 757 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 758 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 759 warnx("peer certificate is not %s", tls_expecthash); 760 else if (gotcert && tls_expectname && 761 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 762 warnx("name (%s) not found in client cert", 763 tls_expectname); 764 else { 765 return tls_cctx; 766 } 767 } 768 return NULL; 769 } 770 771 /* 772 * unix_connect() 773 * Returns a socket connected to a local unix socket. Returns -1 on failure. 774 */ 775 int 776 unix_connect(char *path) 777 { 778 struct sockaddr_un s_un; 779 int s, save_errno; 780 781 if (uflag) { 782 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 783 return (-1); 784 } else { 785 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 786 return (-1); 787 } 788 789 memset(&s_un, 0, sizeof(struct sockaddr_un)); 790 s_un.sun_family = AF_UNIX; 791 792 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 793 sizeof(s_un.sun_path)) { 794 close(s); 795 errno = ENAMETOOLONG; 796 return (-1); 797 } 798 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 799 save_errno = errno; 800 close(s); 801 errno = save_errno; 802 return (-1); 803 } 804 return (s); 805 806 } 807 808 /* 809 * unix_listen() 810 * Create a unix domain socket, and listen on it. 811 */ 812 int 813 unix_listen(char *path) 814 { 815 int s; 816 if ((s = unix_bind(path, 0)) < 0) 817 return (-1); 818 819 if (listen(s, 5) < 0) { 820 close(s); 821 return (-1); 822 } 823 return (s); 824 } 825 826 /* 827 * remote_connect() 828 * Returns a socket connected to a remote host. Properly binds to a local 829 * port or source address if needed. Returns -1 on failure. 830 */ 831 int 832 remote_connect(const char *host, const char *port, struct addrinfo hints) 833 { 834 struct addrinfo *res, *res0; 835 int s, error, on = 1, save_errno; 836 837 if ((error = getaddrinfo(host, port, &hints, &res))) 838 errx(1, "getaddrinfo: %s", gai_strerror(error)); 839 840 res0 = res; 841 do { 842 if ((s = socket(res0->ai_family, res0->ai_socktype | 843 SOCK_NONBLOCK, res0->ai_protocol)) < 0) 844 continue; 845 846 /* Bind to a local port or source address if specified. */ 847 if (sflag || pflag) { 848 struct addrinfo ahints, *ares; 849 850 /* try SO_BINDANY, but don't insist */ 851 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 852 memset(&ahints, 0, sizeof(struct addrinfo)); 853 ahints.ai_family = res0->ai_family; 854 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 855 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 856 ahints.ai_flags = AI_PASSIVE; 857 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 858 errx(1, "getaddrinfo: %s", gai_strerror(error)); 859 860 if (bind(s, (struct sockaddr *)ares->ai_addr, 861 ares->ai_addrlen) < 0) 862 err(1, "bind failed"); 863 freeaddrinfo(ares); 864 } 865 866 set_common_sockopts(s, res0->ai_family); 867 868 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 869 break; 870 if (vflag) 871 warn("connect to %s port %s (%s) failed", host, port, 872 uflag ? "udp" : "tcp"); 873 874 save_errno = errno; 875 close(s); 876 errno = save_errno; 877 s = -1; 878 } while ((res0 = res0->ai_next) != NULL); 879 880 freeaddrinfo(res); 881 882 return (s); 883 } 884 885 int 886 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 887 { 888 struct pollfd pfd; 889 socklen_t optlen; 890 int optval; 891 int ret; 892 893 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 894 pfd.fd = s; 895 pfd.events = POLLOUT; 896 if ((ret = poll(&pfd, 1, timeout)) == 1) { 897 optlen = sizeof(optval); 898 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 899 &optval, &optlen)) == 0) { 900 errno = optval; 901 ret = optval == 0 ? 0 : -1; 902 } 903 } else if (ret == 0) { 904 errno = ETIMEDOUT; 905 ret = -1; 906 } else 907 err(1, "poll failed"); 908 } 909 910 return (ret); 911 } 912 913 /* 914 * local_listen() 915 * Returns a socket listening on a local port, binds to specified source 916 * address. Returns -1 on failure. 917 */ 918 int 919 local_listen(char *host, char *port, struct addrinfo hints) 920 { 921 struct addrinfo *res, *res0; 922 int s, ret, x = 1, save_errno; 923 int error; 924 925 /* Allow nodename to be null. */ 926 hints.ai_flags |= AI_PASSIVE; 927 928 /* 929 * In the case of binding to a wildcard address 930 * default to binding to an ipv4 address. 931 */ 932 if (host == NULL && hints.ai_family == AF_UNSPEC) 933 hints.ai_family = AF_INET; 934 935 if ((error = getaddrinfo(host, port, &hints, &res))) 936 errx(1, "getaddrinfo: %s", gai_strerror(error)); 937 938 res0 = res; 939 do { 940 if ((s = socket(res0->ai_family, res0->ai_socktype, 941 res0->ai_protocol)) < 0) 942 continue; 943 944 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 945 if (ret == -1) 946 err(1, NULL); 947 948 set_common_sockopts(s, res0->ai_family); 949 950 if (bind(s, (struct sockaddr *)res0->ai_addr, 951 res0->ai_addrlen) == 0) 952 break; 953 954 save_errno = errno; 955 close(s); 956 errno = save_errno; 957 s = -1; 958 } while ((res0 = res0->ai_next) != NULL); 959 960 if (!uflag && s != -1) { 961 if (listen(s, 1) < 0) 962 err(1, "listen"); 963 } 964 965 freeaddrinfo(res); 966 967 return (s); 968 } 969 970 /* 971 * readwrite() 972 * Loop that polls on the network file descriptor and stdin. 973 */ 974 void 975 readwrite(int net_fd, struct tls *tls_ctx) 976 { 977 struct pollfd pfd[4]; 978 int stdin_fd = STDIN_FILENO; 979 int stdout_fd = STDOUT_FILENO; 980 unsigned char netinbuf[BUFSIZE]; 981 size_t netinbufpos = 0; 982 unsigned char stdinbuf[BUFSIZE]; 983 size_t stdinbufpos = 0; 984 int n, num_fds; 985 ssize_t ret; 986 987 /* don't read from stdin if requested */ 988 if (dflag) 989 stdin_fd = -1; 990 991 /* stdin */ 992 pfd[POLL_STDIN].fd = stdin_fd; 993 pfd[POLL_STDIN].events = POLLIN; 994 995 /* network out */ 996 pfd[POLL_NETOUT].fd = net_fd; 997 pfd[POLL_NETOUT].events = 0; 998 999 /* network in */ 1000 pfd[POLL_NETIN].fd = net_fd; 1001 pfd[POLL_NETIN].events = POLLIN; 1002 1003 /* stdout */ 1004 pfd[POLL_STDOUT].fd = stdout_fd; 1005 pfd[POLL_STDOUT].events = 0; 1006 1007 while (1) { 1008 /* both inputs are gone, buffers are empty, we are done */ 1009 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1010 stdinbufpos == 0 && netinbufpos == 0) { 1011 close(net_fd); 1012 return; 1013 } 1014 /* both outputs are gone, we can't continue */ 1015 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1016 close(net_fd); 1017 return; 1018 } 1019 /* listen and net in gone, queues empty, done */ 1020 if (lflag && pfd[POLL_NETIN].fd == -1 && 1021 stdinbufpos == 0 && netinbufpos == 0) { 1022 close(net_fd); 1023 return; 1024 } 1025 1026 /* help says -i is for "wait between lines sent". We read and 1027 * write arbitrary amounts of data, and we don't want to start 1028 * scanning for newlines, so this is as good as it gets */ 1029 if (iflag) 1030 sleep(iflag); 1031 1032 /* poll */ 1033 num_fds = poll(pfd, 4, timeout); 1034 1035 /* treat poll errors */ 1036 if (num_fds == -1) { 1037 close(net_fd); 1038 err(1, "polling error"); 1039 } 1040 1041 /* timeout happened */ 1042 if (num_fds == 0) 1043 return; 1044 1045 /* treat socket error conditions */ 1046 for (n = 0; n < 4; n++) { 1047 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1048 pfd[n].fd = -1; 1049 } 1050 } 1051 /* reading is possible after HUP */ 1052 if (pfd[POLL_STDIN].events & POLLIN && 1053 pfd[POLL_STDIN].revents & POLLHUP && 1054 !(pfd[POLL_STDIN].revents & POLLIN)) 1055 pfd[POLL_STDIN].fd = -1; 1056 1057 if (pfd[POLL_NETIN].events & POLLIN && 1058 pfd[POLL_NETIN].revents & POLLHUP && 1059 !(pfd[POLL_NETIN].revents & POLLIN)) 1060 pfd[POLL_NETIN].fd = -1; 1061 1062 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1063 if (Nflag) 1064 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1065 pfd[POLL_NETOUT].fd = -1; 1066 } 1067 /* if HUP, stop watching stdout */ 1068 if (pfd[POLL_STDOUT].revents & POLLHUP) 1069 pfd[POLL_STDOUT].fd = -1; 1070 /* if no net out, stop watching stdin */ 1071 if (pfd[POLL_NETOUT].fd == -1) 1072 pfd[POLL_STDIN].fd = -1; 1073 /* if no stdout, stop watching net in */ 1074 if (pfd[POLL_STDOUT].fd == -1) { 1075 if (pfd[POLL_NETIN].fd != -1) 1076 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1077 pfd[POLL_NETIN].fd = -1; 1078 } 1079 1080 /* try to read from stdin */ 1081 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1082 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1083 &stdinbufpos, NULL); 1084 if (ret == TLS_WANT_POLLIN) 1085 pfd[POLL_STDIN].events = POLLIN; 1086 else if (ret == TLS_WANT_POLLOUT) 1087 pfd[POLL_STDIN].events = POLLOUT; 1088 else if (ret == 0 || ret == -1) 1089 pfd[POLL_STDIN].fd = -1; 1090 /* read something - poll net out */ 1091 if (stdinbufpos > 0) 1092 pfd[POLL_NETOUT].events = POLLOUT; 1093 /* filled buffer - remove self from polling */ 1094 if (stdinbufpos == BUFSIZE) 1095 pfd[POLL_STDIN].events = 0; 1096 } 1097 /* try to write to network */ 1098 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1099 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1100 &stdinbufpos, tls_ctx); 1101 if (ret == TLS_WANT_POLLIN) 1102 pfd[POLL_NETOUT].events = POLLIN; 1103 else if (ret == TLS_WANT_POLLOUT) 1104 pfd[POLL_NETOUT].events = POLLOUT; 1105 else if (ret == -1) 1106 pfd[POLL_NETOUT].fd = -1; 1107 /* buffer empty - remove self from polling */ 1108 if (stdinbufpos == 0) 1109 pfd[POLL_NETOUT].events = 0; 1110 /* buffer no longer full - poll stdin again */ 1111 if (stdinbufpos < BUFSIZE) 1112 pfd[POLL_STDIN].events = POLLIN; 1113 } 1114 /* try to read from network */ 1115 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1116 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1117 &netinbufpos, tls_ctx); 1118 if (ret == TLS_WANT_POLLIN) 1119 pfd[POLL_NETIN].events = POLLIN; 1120 else if (ret == TLS_WANT_POLLOUT) 1121 pfd[POLL_NETIN].events = POLLOUT; 1122 else if (ret == -1) 1123 pfd[POLL_NETIN].fd = -1; 1124 /* eof on net in - remove from pfd */ 1125 if (ret == 0) { 1126 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1127 pfd[POLL_NETIN].fd = -1; 1128 } 1129 /* read something - poll stdout */ 1130 if (netinbufpos > 0) 1131 pfd[POLL_STDOUT].events = POLLOUT; 1132 /* filled buffer - remove self from polling */ 1133 if (netinbufpos == BUFSIZE) 1134 pfd[POLL_NETIN].events = 0; 1135 /* handle telnet */ 1136 if (tflag) 1137 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1138 netinbufpos); 1139 } 1140 /* try to write to stdout */ 1141 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1142 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1143 &netinbufpos, NULL); 1144 if (ret == TLS_WANT_POLLIN) 1145 pfd[POLL_STDOUT].events = POLLIN; 1146 else if (ret == TLS_WANT_POLLOUT) 1147 pfd[POLL_STDOUT].events = POLLOUT; 1148 else if (ret == -1) 1149 pfd[POLL_STDOUT].fd = -1; 1150 /* buffer empty - remove self from polling */ 1151 if (netinbufpos == 0) 1152 pfd[POLL_STDOUT].events = 0; 1153 /* buffer no longer full - poll net in again */ 1154 if (netinbufpos < BUFSIZE) 1155 pfd[POLL_NETIN].events = POLLIN; 1156 } 1157 1158 /* stdin gone and queue empty? */ 1159 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1160 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1161 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1162 pfd[POLL_NETOUT].fd = -1; 1163 } 1164 /* net in gone and queue empty? */ 1165 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1166 pfd[POLL_STDOUT].fd = -1; 1167 } 1168 } 1169 } 1170 1171 ssize_t 1172 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1173 { 1174 ssize_t n; 1175 ssize_t adjust; 1176 1177 if (tls) 1178 n = tls_write(tls, buf, *bufpos); 1179 else { 1180 n = write(fd, buf, *bufpos); 1181 /* don't treat EAGAIN, EINTR as error */ 1182 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1183 n = TLS_WANT_POLLOUT; 1184 } 1185 if (n <= 0) 1186 return n; 1187 /* adjust buffer */ 1188 adjust = *bufpos - n; 1189 if (adjust > 0) 1190 memmove(buf, buf + n, adjust); 1191 *bufpos -= n; 1192 return n; 1193 } 1194 1195 ssize_t 1196 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1197 { 1198 size_t num = BUFSIZE - *bufpos; 1199 ssize_t n; 1200 1201 if (tls) 1202 n = tls_read(tls, buf + *bufpos, num); 1203 else { 1204 n = read(fd, buf + *bufpos, num); 1205 /* don't treat EAGAIN, EINTR as error */ 1206 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1207 n = TLS_WANT_POLLIN; 1208 } 1209 if (n <= 0) 1210 return n; 1211 *bufpos += n; 1212 return n; 1213 } 1214 1215 /* 1216 * fdpass() 1217 * Pass the connected file descriptor to stdout and exit. 1218 */ 1219 void 1220 fdpass(int nfd) 1221 { 1222 struct msghdr mh; 1223 union { 1224 struct cmsghdr hdr; 1225 char buf[CMSG_SPACE(sizeof(int))]; 1226 } cmsgbuf; 1227 struct cmsghdr *cmsg; 1228 struct iovec iov; 1229 char c = '\0'; 1230 ssize_t r; 1231 struct pollfd pfd; 1232 1233 /* Avoid obvious stupidity */ 1234 if (isatty(STDOUT_FILENO)) 1235 errx(1, "Cannot pass file descriptor to tty"); 1236 1237 bzero(&mh, sizeof(mh)); 1238 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1239 bzero(&iov, sizeof(iov)); 1240 1241 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1242 mh.msg_controllen = sizeof(cmsgbuf.buf); 1243 cmsg = CMSG_FIRSTHDR(&mh); 1244 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1245 cmsg->cmsg_level = SOL_SOCKET; 1246 cmsg->cmsg_type = SCM_RIGHTS; 1247 *(int *)CMSG_DATA(cmsg) = nfd; 1248 1249 iov.iov_base = &c; 1250 iov.iov_len = 1; 1251 mh.msg_iov = &iov; 1252 mh.msg_iovlen = 1; 1253 1254 bzero(&pfd, sizeof(pfd)); 1255 pfd.fd = STDOUT_FILENO; 1256 pfd.events = POLLOUT; 1257 for (;;) { 1258 r = sendmsg(STDOUT_FILENO, &mh, 0); 1259 if (r == -1) { 1260 if (errno == EAGAIN || errno == EINTR) { 1261 if (poll(&pfd, 1, -1) == -1) 1262 err(1, "poll"); 1263 continue; 1264 } 1265 err(1, "sendmsg"); 1266 } else if (r != 1) 1267 errx(1, "sendmsg: unexpected return value %zd", r); 1268 else 1269 break; 1270 } 1271 exit(0); 1272 } 1273 1274 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1275 void 1276 atelnet(int nfd, unsigned char *buf, unsigned int size) 1277 { 1278 unsigned char *p, *end; 1279 unsigned char obuf[4]; 1280 1281 if (size < 3) 1282 return; 1283 end = buf + size - 2; 1284 1285 for (p = buf; p < end; p++) { 1286 if (*p != IAC) 1287 continue; 1288 1289 obuf[0] = IAC; 1290 p++; 1291 if ((*p == WILL) || (*p == WONT)) 1292 obuf[1] = DONT; 1293 else if ((*p == DO) || (*p == DONT)) 1294 obuf[1] = WONT; 1295 else 1296 continue; 1297 1298 p++; 1299 obuf[2] = *p; 1300 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1301 warn("Write Error!"); 1302 } 1303 } 1304 1305 1306 int 1307 strtoport(char *portstr, int udp) 1308 { 1309 struct servent *entry; 1310 const char *errstr; 1311 char *proto; 1312 int port = -1; 1313 1314 proto = udp ? "udp" : "tcp"; 1315 1316 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1317 if (errstr == NULL) 1318 return port; 1319 if (errno != EINVAL) 1320 errx(1, "port number %s: %s", errstr, portstr); 1321 if ((entry = getservbyname(portstr, proto)) == NULL) 1322 errx(1, "service \"%s\" unknown", portstr); 1323 return ntohs(entry->s_port); 1324 } 1325 1326 /* 1327 * build_ports() 1328 * Build an array of ports in portlist[], listing each port 1329 * that we should try to connect to. 1330 */ 1331 void 1332 build_ports(char *p) 1333 { 1334 char *n; 1335 int hi, lo, cp; 1336 int x = 0; 1337 1338 if ((n = strchr(p, '-')) != NULL) { 1339 *n = '\0'; 1340 n++; 1341 1342 /* Make sure the ports are in order: lowest->highest. */ 1343 hi = strtoport(n, uflag); 1344 lo = strtoport(p, uflag); 1345 if (lo > hi) { 1346 cp = hi; 1347 hi = lo; 1348 lo = cp; 1349 } 1350 1351 /* 1352 * Initialize portlist with a random permutation. Based on 1353 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1354 */ 1355 if (rflag) { 1356 for (x = 0; x <= hi - lo; x++) { 1357 cp = arc4random_uniform(x + 1); 1358 portlist[x] = portlist[cp]; 1359 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1360 err(1, "asprintf"); 1361 } 1362 } else { /* Load ports sequentially. */ 1363 for (cp = lo; cp <= hi; cp++) { 1364 if (asprintf(&portlist[x], "%d", cp) < 0) 1365 err(1, "asprintf"); 1366 x++; 1367 } 1368 } 1369 } else { 1370 char *tmp; 1371 1372 hi = strtoport(p, uflag); 1373 if (asprintf(&tmp, "%d", hi) != -1) 1374 portlist[0] = tmp; 1375 else 1376 err(1, NULL); 1377 } 1378 } 1379 1380 /* 1381 * udptest() 1382 * Do a few writes to see if the UDP port is there. 1383 * Fails once PF state table is full. 1384 */ 1385 int 1386 udptest(int s) 1387 { 1388 int i, ret; 1389 1390 for (i = 0; i <= 3; i++) { 1391 if (write(s, "X", 1) == 1) 1392 ret = 1; 1393 else 1394 ret = -1; 1395 } 1396 return (ret); 1397 } 1398 1399 void 1400 set_common_sockopts(int s, int af) 1401 { 1402 int x = 1; 1403 1404 if (Sflag) { 1405 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1406 &x, sizeof(x)) == -1) 1407 err(1, NULL); 1408 } 1409 if (Dflag) { 1410 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1411 &x, sizeof(x)) == -1) 1412 err(1, NULL); 1413 } 1414 if (Tflag != -1) { 1415 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1416 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1417 err(1, "set IP ToS"); 1418 1419 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1420 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1421 err(1, "set IPv6 traffic class"); 1422 } 1423 if (Iflag) { 1424 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1425 &Iflag, sizeof(Iflag)) == -1) 1426 err(1, "set TCP receive buffer size"); 1427 } 1428 if (Oflag) { 1429 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1430 &Oflag, sizeof(Oflag)) == -1) 1431 err(1, "set TCP send buffer size"); 1432 } 1433 1434 if (ttl != -1) { 1435 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1436 IP_TTL, &ttl, sizeof(ttl))) 1437 err(1, "set IP TTL"); 1438 1439 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1440 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1441 err(1, "set IPv6 unicast hops"); 1442 } 1443 1444 if (minttl != -1) { 1445 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1446 IP_MINTTL, &minttl, sizeof(minttl))) 1447 err(1, "set IP min TTL"); 1448 1449 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1450 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1451 err(1, "set IPv6 min hop count"); 1452 } 1453 } 1454 1455 int 1456 map_tos(char *s, int *val) 1457 { 1458 /* DiffServ Codepoints and other TOS mappings */ 1459 const struct toskeywords { 1460 const char *keyword; 1461 int val; 1462 } *t, toskeywords[] = { 1463 { "af11", IPTOS_DSCP_AF11 }, 1464 { "af12", IPTOS_DSCP_AF12 }, 1465 { "af13", IPTOS_DSCP_AF13 }, 1466 { "af21", IPTOS_DSCP_AF21 }, 1467 { "af22", IPTOS_DSCP_AF22 }, 1468 { "af23", IPTOS_DSCP_AF23 }, 1469 { "af31", IPTOS_DSCP_AF31 }, 1470 { "af32", IPTOS_DSCP_AF32 }, 1471 { "af33", IPTOS_DSCP_AF33 }, 1472 { "af41", IPTOS_DSCP_AF41 }, 1473 { "af42", IPTOS_DSCP_AF42 }, 1474 { "af43", IPTOS_DSCP_AF43 }, 1475 { "critical", IPTOS_PREC_CRITIC_ECP }, 1476 { "cs0", IPTOS_DSCP_CS0 }, 1477 { "cs1", IPTOS_DSCP_CS1 }, 1478 { "cs2", IPTOS_DSCP_CS2 }, 1479 { "cs3", IPTOS_DSCP_CS3 }, 1480 { "cs4", IPTOS_DSCP_CS4 }, 1481 { "cs5", IPTOS_DSCP_CS5 }, 1482 { "cs6", IPTOS_DSCP_CS6 }, 1483 { "cs7", IPTOS_DSCP_CS7 }, 1484 { "ef", IPTOS_DSCP_EF }, 1485 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1486 { "lowdelay", IPTOS_LOWDELAY }, 1487 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1488 { "reliability", IPTOS_RELIABILITY }, 1489 { "throughput", IPTOS_THROUGHPUT }, 1490 { NULL, -1 }, 1491 }; 1492 1493 for (t = toskeywords; t->keyword != NULL; t++) { 1494 if (strcmp(s, t->keyword) == 0) { 1495 *val = t->val; 1496 return (1); 1497 } 1498 } 1499 1500 return (0); 1501 } 1502 1503 int 1504 map_tls(char *s, int *val) 1505 { 1506 const struct tlskeywords { 1507 const char *keyword; 1508 int val; 1509 } *t, tlskeywords[] = { 1510 { "tlslegacy", TLS_LEGACY }, 1511 { "noverify", TLS_NOVERIFY }, 1512 { "noname", TLS_NONAME }, 1513 { "clientcert", TLS_CCERT}, 1514 { NULL, -1 }, 1515 }; 1516 1517 for (t = tlskeywords; t->keyword != NULL; t++) { 1518 if (strcmp(s, t->keyword) == 0) { 1519 *val |= t->val; 1520 return (1); 1521 } 1522 } 1523 return (0); 1524 } 1525 1526 void 1527 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1528 { 1529 time_t t; 1530 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1531 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1532 fprintf(stderr, "Peer name: %s\n", 1533 tls_expectname ? tls_expectname : host); 1534 if (tls_peer_cert_subject(tls_ctx)) 1535 fprintf(stderr, "Subject: %s\n", 1536 tls_peer_cert_subject(tls_ctx)); 1537 if (tls_peer_cert_issuer(tls_ctx)) 1538 fprintf(stderr, "Issuer: %s\n", 1539 tls_peer_cert_issuer(tls_ctx)); 1540 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1541 fprintf(stderr, "Valid From: %s", ctime(&t)); 1542 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1543 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1544 if (tls_peer_cert_hash(tls_ctx)) 1545 fprintf(stderr, "Cert Hash: %s\n", 1546 tls_peer_cert_hash(tls_ctx)); 1547 } 1548 1549 void 1550 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1551 { 1552 char remote_host[NI_MAXHOST]; 1553 char remote_port[NI_MAXSERV]; 1554 int herr; 1555 int flags = NI_NUMERICSERV; 1556 1557 if (path != NULL) { 1558 fprintf(stderr, "Connection on %s received!\n", path); 1559 return; 1560 } 1561 1562 if (nflag) 1563 flags |= NI_NUMERICHOST; 1564 1565 if ((herr = getnameinfo(sa, salen, 1566 remote_host, sizeof(remote_host), 1567 remote_port, sizeof(remote_port), 1568 flags)) != 0) { 1569 if (herr == EAI_SYSTEM) 1570 err(1, "getnameinfo"); 1571 else 1572 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1573 } 1574 1575 fprintf(stderr, 1576 "Connection from %s %s " 1577 "received!\n", remote_host, remote_port); 1578 } 1579 1580 void 1581 help(void) 1582 { 1583 usage(0); 1584 fprintf(stderr, "\tCommand Summary:\n\ 1585 \t-4 Use IPv4\n\ 1586 \t-6 Use IPv6\n\ 1587 \t-C certfile Public key file\n\ 1588 \t-c Use TLS\n\ 1589 \t-D Enable the debug socket option\n\ 1590 \t-d Detach from stdin\n\ 1591 \t-e name\t Required name in peer certificate\n\ 1592 \t-F Pass socket fd\n\ 1593 \t-H hash\t Hash string of peer certificate\n\ 1594 \t-h This help text\n\ 1595 \t-I length TCP receive buffer length\n\ 1596 \t-i interval Delay interval for lines sent, ports scanned\n\ 1597 \t-K keyfile Private key file\n\ 1598 \t-k Keep inbound sockets open for multiple connects\n\ 1599 \t-l Listen mode, for inbound connects\n\ 1600 \t-M ttl Outgoing TTL / Hop Limit\n\ 1601 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1602 \t-N Shutdown the network socket after EOF on stdin\n\ 1603 \t-n Suppress name/port resolutions\n\ 1604 \t-O length TCP send buffer length\n\ 1605 \t-P proxyuser\tUsername for proxy authentication\n\ 1606 \t-p port\t Specify local port for remote connects\n\ 1607 \t-R CAfile CA bundle\n\ 1608 \t-r Randomize remote ports\n\ 1609 \t-S Enable the TCP MD5 signature option\n\ 1610 \t-s source Local source address\n\ 1611 \t-T keyword TOS value or TLS options\n\ 1612 \t-t Answer TELNET negotiation\n\ 1613 \t-U Use UNIX domain socket\n\ 1614 \t-u UDP mode\n\ 1615 \t-V rtable Specify alternate routing table\n\ 1616 \t-v Verbose\n\ 1617 \t-w timeout Timeout for connects and final net reads\n\ 1618 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1619 \t-x addr[:port]\tSpecify proxy address and port\n\ 1620 \t-z Zero-I/O mode [used for scanning]\n\ 1621 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1622 exit(1); 1623 } 1624 1625 void 1626 usage(int ret) 1627 { 1628 fprintf(stderr, 1629 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1630 "[-H hash] [-I length]\n" 1631 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1632 "\t [-P proxy_username] [-p source_port] [-R CAfile] [-s source]\n" 1633 "\t [-T keyword] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1634 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1635 if (ret) 1636 exit(1); 1637 } 1638